JBJ is maybe the best fielding CF'er in Red Sox history. I say "maybe" because the sample size is still too small to compare to longtime Sox greats. There's no doubt in my mind, JBJ will go down in Sox history as the best defensive CF'er ever, assuming he doesn't get hurt or traded.
His bat at the major league level has always been the shady area. Anyone who knows me, knows that even a 3 month sample size proves nothing to me, but JBJ's last 3 months have been beyond our wildest expectations. If he keeps this up, he may become the greatest all around CF'er in Sox history.
Note: I'm not predicting this to happen. I'm not setting expectations so high, he's bound to disappoint. I personally think he'll end up around .800 to .825 career.